Anne Gadermann

Psychopathology is known to fluctuate throughout childhood and adolescence, in association with a variety of intrinsic (e.g., genetic) and extrinsic (e.g., environmental) factors. DNA methylation (DNAm) is a commonly studied epigenetic modification that can reflect the interplay between genetics and environments. DNAm is a stable, reversible mark added onto DNA that can regulate gene expression and may serve as a biomarker of psychopathology. Many studies have identified links between DNAm and childhood and adolescent psychopathology, but most have been limited by assessing narrow timeframes. The present study harnessed a wealth of longitudinal data from a community-based cohort of children in Wisconsin (n=170) to examine the General Psychopathology Factor (GPF) – a broad construct capturing shared variance between psychiatric symptoms – across childhood and adolescence, in relation to DNAm from buccal epithelial cells collected at age 18. To determine which GPF timepoint (of 7 timepoints across age 9-18) or GPF trajectory (of 5 derived trajectory measures) provided the best explanation of age 18 DNAm patterns, a two-phase comparative statistical approach was employed, consisting of screening measures for high-dimensional data and the Structured Life-Course Modelling Approach (SLCMA). The SLCMA identified which GPF measure explained the most DNAm variation at 298,415 methylation sites (CpGs). At 12,910 CpGs, the selected GPF measure explained more DNAm variation than expected by chance (R² > 3.7%). After multiple test correction, 486 medium-confidence (Padjusted
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This thesis is focused on characterizing differences in pharmacological treatment among immigrant and non-immigrant children with Attention-Deficit/Hyperactivity Disorder (ADHD). Multimodal approaches combining psychosocial and pharmacological interventions are recommended for the treatment of ADHD. Among pharmacological treatments, stimulant medications are among the most common and efficacious drug therapy used to manage ADHD symptoms. However, there are concerns around increasing use of medications, such as atypical antipsychotics, that lack substantive evidence and are not currently approved by Health Canada for the treatment of ADHD. This thesis has two main studies: First, scoping review methodology was used to examine longitudinal trends, prevalence, tolerability, and safety of atypical antipsychotics among children with ADHD. No studies were identified relating to atypical antipsychotic use specific to immigrant children with ADHD, even though this review found that many children with ADHD still receive atypical antipsychotics. Atypical antipsychotic medications are often used to manage psychiatric comorbidity and/or aggressive and impulsive symptoms associated with ADHD. However, there is little evidence regarding the safety and tolerability of atypical antipsychotics to support the use of these medications as a first-line intervention among children diagnosed with ADHD. Second, differences in first-line stimulant and atypical antipsychotic prescribing practices were examined among newly diagnosed immigrant and non-immigrant children with ADHD, living in British Columbia, Canada. Immigrant children were less likely than non-immigrant children to be dispensed a stimulant medication prescription in the 30-days following an incident diagnosis of ADHD. Among children, being older, male, and receiving treatment from a psychiatrist was associated with being dispensed an atypical antipsychotic prescription as a first-line intervention within 30-days of diagnosis. A latent class analysis (LCA) was conducted to account for sources of variability that may be associated with ADHD treatment. A high proportion of children with ADHD were not dispensed any prescription medications. Non-migrant boys had a 68% increased likelihood of being treated with atypical antipsychotics compared to their migrant counterparts. Together, the studies incorporated in this thesis underline the importance of examining relationships between structural determinants of health, health equity, and ADHD-related prescribing practices.

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Background: Emotional development during middle childhood is associated with thriving in adolescence and adulthood. Previous research has demonstrated an association between participation in organized activities (OA) and positive development, including emotional wellbeing. However, there is an absence of literature evaluating the role of immigrant background (i.e., immigrant-origin or non-immigrant) in the relationship between OA participation and emotional wellbeing. The objectives of this study were to test for an association between OA participation and immigrant background, to measure the association between OA participation and emotional wellbeing indicators (life satisfaction, depressive symptoms), and to examine whether the relationship between OA participation and wellbeing was dependent on immigrant background among a sample of schoolchildren. Methods: This study’s sample was composed of 14,406 Grade 7 children in British Columbia (BC) who completed the Middle Years Development Instrument (MDI), a population-level self-report survey designed to measure children’s wellbeing and assets, between the 2012/2013 and 2016/2017 school years. Children who were born outside of Canada or who had at least one foreign-born parent were classified as immigrant-origin. Odds ratios and the χ² test were reported to test for an association between OA participation and immigrant background. Multiple linear regression analyses were used to examine the association between participation in OAs and indicators of emotional wellbeing and to examine whether this relationship varied based on immigrant background, while controlling for demographic factors. Results: Immigrant background was not associated with overall OA participation. Immigrant background was associated with participation in educational activities, arts and music lessons,and individual sports, while team sports participation was associated with non-immigrant background. Immigrant background modified the association between overall OA participation and emotional wellbeing, with stronger and beneficial associations generally observed among non-immigrant children. Conclusions: This study identified a stronger association between OA participation and emotional wellbeing among non-immigrant children than immigrant-origin children. The results underscore the importance of designing OAs sensitive to the diversity of schoolchildren, including those of immigrant-origin. Further research identifying factors that explain differences in this association based on immigrant background can inform the development of OAs that support the emotional wellbeing of immigrant-origin children.

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Post-secondary students are typically assuming greater life responsibilities and independence, which can become emotionally overwhelming, resulting in a high prevalence of psychosocial issues. At a time when many young adults are moving away from their support networks and transitioning from pediatric to adult health care systems, there is a perceived lack of resources and numerous barriers to mental health treatment. A digital psychosocial self-assessment and guidance tool for post-secondary students (HEARTSMAP-U) was adapted to address this growing concern. HEARTSMAP-U has already undergone comprehensive adaptation and evaluation work among both a broad population of clinicians who support young adults in post-secondary education, as well as among post-secondary students themselves. Through a multiphasic study, this research aimed to 1) evaluate the inter-rater reliability of HEARTSMAP-U among young adults pursuing post-secondary education, as applied to a set of fictional cases, and 2) evaluate, on the same set of fictional cases, the scoring agreement between student and clinician assessors. In Phase 1 (n = 15), an iterative process was used to evaluate the fictional vignettes for comprehensiveness and clarity. Feedback received was reviewed and incorporated into the next version of the vignette and this process was conducted four times until all comments were positive and saturated. In Phase 2 (n = 34), HEARTSMAP-U’s inter-rater reliability was evaluated among post-secondary students. Students displayed substantial to near perfect inter-rater scoring agreement in applying HEARTSMAP-U to the finalized fictional clinical vignettes, with weighted kappas on tool domains ranging from 0.72 (Student Health; 95% CI: 0.71, 0.73) to 0.81 (Psychiatry; 95% CI: 0.80, 0.82). In Phase 3, a clinician applied HEARTSMAP-U to the same vignettes and a large proportion of scoring agreement was found between student and clinician responses (median range 0.82-0.85) on concern severity and on whether the individual described in the vignette had resources in place (97%). Together, these results indicate that HEARTSMAP-U can be consistently interpreted by young adults pursuing post-secondary education. These study results will add to HEARTSMAP-U’s ongoing evaluation in which HEARTSMAP-U’s predictive validity will be assessed.

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Background: Previous research has shown that predominantly plant-based diets can co-benefit human health and the health of the planet. However, studies on their association with mental health are scarce even though mental health disorders contribute substantially to the global burden of disease. This study utilized a biopsychosocial frame to assess this association among undergraduate students as this population is highly vulnerable to mental disorders and simultaneously most likely to adopt a plant-based diet. Methods: Cross-sectional survey data were collected that included assessments of depression (PHQ-9), anxiety (GAD-7), and quality of life. Diet was measured through a posteriori self-reported dietary patterns as well as through self-identification with a diet preference category (such as pescatarian, vegetarian, or vegan). Multiple regression analysis was used to test whether plant-based diet preferences or diet patterns were associated with mental health outcomes, controlling for age, gender, ethnicity, sleep, physical activity, body image, stress, stressful life events, and social support. Data were further explored to uncover trends among and characteristics of those following a plant-based diet.Findings: In this sample (n=339), the majority of students (87.4%, n=298) indicated that they had good to excellent quality of life, while 20.4% (n=69) screened positive for moderately severe or severe depression and 32.4% (n=110) screened positive for moderate or severe anxiety (generally indicating necessity of a clinical intervention). Three dominant dietary patterns were found (plant-based, animal-based, and processed foods); 28.1% (n=95) of participants self-identified as following a predominantly plant-based diet. After controlling for covariables, most notably social support, we found a significant association between the processed food diet pattern and depression (z-score β=.21, p≤.001; adj. R²=.39) and anxiety (z-score β=.14; p≤.001; adj. R²=.32) while no association emerged between diet preference categories and mental wellbeing.Conclusions: This study showed that diet intake rather than preference category should be considered when examining relationships with mental health outcomes. It further pointed at the importance of conceptualizing diet as a health behaviour that is embedded in a multidimensional biopsychosocial framework and an integrated model for future inquiry in this field was proposed.

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